The inclusion of inflatable safety restraint devices, or airbags, is now a legal requirement for many new vehicles. Airbags are typically installed in the steering wheel dashboard, and at other positions in the vehicle. In the event of an accident, an accelerometer within the vehicle measures the abnormal deceleration and triggers the expulsion of rapidly expanding gases from an inflator. The expanding gases fill the airbags, which immediately inflate in front of the driver and passenger to protect them from impact against the windshield, dashboard, or other surfaces of the vehicle interior. Side impact airbags, known as inflatable curtains, have also been developed in response to the need for protection from impacts in a lateral direction, or against the side of the vehicle.
Conventional inflatable curtains often use a rigid “gas guide,” such as made from metal or plastic, to direct gas from the inflator to the airbag cushion. The gas guide is a tube or other gas channel that directs the flow of the gas. The gas guide is manufactured separate from the airbag cushion and, thus, increases tooling and equipment costs associated with the overall cost of the inflatable curtain. The rigid gas guide also increases the weight of the airbag unit.
Textile gas guides have also been developed. Known textile gas guides are typically folded piece of material that is sewn along the edge to create a channel for the inflation gas. FIGS. 1A-2D illustrate previously known textile gas guides.
FIG. 1A illustrates a layout view of an unsewn, previously known textile gas guide. The gas guide 20 is referred to as a “midfill” gas guide. The gas guide 20 has sides 20a and 20b. Side 20a is folded over onto side 20b along fold line 22. FIG. 1B illustrates sew seam 24 used to create an outside edge of textile gas guide 20. Textile gas guide 20 also includes sew seam 26 and sew seams 27a, 27b, and 27c. Sew seams 27a, 27b, and 27c may be stitches that break. In other embodiments, the seams may be used to support a rigid gas guide (not shown) that may be finserted into the textile gas guide 20. The sew seams 27a, 27b, 27c receive this metal gas guide.
FIGS. 1C and 1D illustrates a cross-sectional slice taken along the line 1C-1C of FIG. 1B. FIG. 1C illustrates textile gas guide 20 in an uninflated state. FIG. 1D illustrates textile gas guide 20 in a hypothetical inflated state as if a rigid gas guide were not present. As textile gas guide 20 fills with gas during deployment, sides 20a and 20b attempt to separate and sew seam 24 is placed under tensile stress. This tensile stress (peel stress) is shown with arrow 23. If sew seam 24 were exposed to the full pressure and flow of an inflator, sew seam 24 may fail under the tensile stress.
FIG. 2A illustrates a layout view of an unsewn, previously known textile gas guide 40 having sides 40a and 40b and flaps 40c and 40d. The gas guide 40 can be an “endfill” gas guide or a “centerfill” gas guide. Side 40a is folded over on side 40b along fold line 42. Flaps 40c and 40d are folded over onto side 40a along fold lines 43a and 43b to create a double folded edge. FIG. 2B illustrates sew seam 44 that creates an outside edge of textile gas guide 40. Textile gas guide 40 also includes sew seam 46. FIGS. 2C and 2D illustrates a cross-sectional slice taken along the line 2C-2C of FIG. 2B. FIG. 2C illustrates textile gas guide 40 in an uninflated state. FIG. 2D illustrates textile gas guide 40 in a hypothetical inflated state as if a rigid gas guide were not present. As textile gas guide 40 fills with gas during inflation, sides 40a and 40b attempt to separate and sew seam 44 is placed under tensile stress. This tensile stress is shown with arrow 23. If sew seam 44 were exposed to the full pressure and flow of an inflator, sew seam 44 may fail under the tensile stress.
Because of the tensile stress 23 that may cause the seams to fail, textile gas guides are often supplemented with a rigid gas guide. The inclusion of this rigid gas guide increases the costs of the airbag system.
Thus, a new type of textile gas guide is needed. Such textile gas guides are disclosed and claimed herein.